New neurons are constantly being produced in the adult brain, but their ability to fine tune connections may be short lived, report Shaoyu Ge, Hongjun Song (JHMI, Baltimore, MD), and colleagues. This short window of plasticity could explain why learning continues throughout life, yet the stability of neuronal circuits is maintained.
Learning and memory require a balance of neuronal plasticity and stability. Too much plasticity and we'd constantly have to learn the same things over and over. Too much stability and we'd have little chance of learning at all. Plasticity peaks in the juvenile brain. By adulthood, however, plasticity is limited.
One area that maintains plasticity is the hippocampus, a region of the brain involved in learning and memory. By labeling adult-born mouse hippocampal neurons and then measuring their electrical activity at regular age increments, Ge et al. found that new neurons are not permanently...
